题解 | #多组_带空格的字符串_T组形式#

from itertools import groupby
import sys

input_data = sys.stdin.read()

lines = input_data.strip().split('\n')

group_num = int(lines[0])

t = 0

while t < group_num:

    str_length = int(lines[2*t+1])

    string = lines[2*t+2].strip()

    res = ''

    for i in range(len(string)-1,-1,-1):

        if string[i] != ' ':

           res += string[i]
    
    print(res)

    t += 1